Is there a way to find the current firmware version number? Either the running version or the version currently installed in
uname -a shows only the kernel version, not the GPU "binary blob."
Steve's answer is correct, but here are some more details that may be of interest.
The firmware version seems to be identified by two pieces of information:
There are two sources for this information:
sudo /opt/vc/bin/vcgencmd version
However, as at least one eagle-eyed contributor here has noted, the 160-bit hash values from the
vcgencmd version command and the release notes do not match. The reason these hash values do not match for any given release date is that the hash values are computed on different file sets REFERENCE:
The Organization (and possibly their suppliers/subcontractors) maintain two repositories for the Raspberry Pi firmware. One of the repositories houses the source code for the RPi firmware, the other repository houses the compiled/binary version of the firmware. The firmware source code repo is unpublished (i.e. it is 'closed-source'); the compiled/binary firmware is housed in this GitHub repo.
And finally to the point of this answer:
If you want to know what version of the firmware is on your RPi, use
sudo /opt/vc/bin/vcgencmd version; i.e. Steve's answer.
If you want to know the latest version of the firmware, check the release notes
NOTE new link for Raspberry Pi OS release notes